Apparatus for the distribution of pulverised fuels



March 14, 1961 R. F. DAVIS APPARATUS FOR THE DISTRIBUTION OF PULVERISED FUELS Filed Nov. 18, 1958 3 Sheets-Sheet 1 INVENTOR Fey/114M BYW'W I ATTORN EY R. F. DAVIS March 14, 1961 APPARATUS FOR THE DISTRIBUTION OF PULVERISED FUELS Filed Nov. 18, 1958 3 Sheets-Sheet 2 INVENTOR Fey/maid F paws, M

AT TOENEY March 14, 1961 V s 2,975,001

APPARATUS FOR THE DISTRIBUTION OF PULVERISED FUELS Filed Nov. 18, 1958 3 Sheets-Sheet 3 (o o o o 5 o 5 8 l O I I O ry 2 o i O I O Q P .4 A T- w Q o o 0 0) BIM W ATTORNEY 2,975,001 1C6 P t nted Mar. 14, 1961 APPARATUS FOR THE DISTRIBUTION OF PULVERISED FUELS Reginald Frank Davis, Littleover, England, assignor to International Combustion (Holdings) Limited, London, England, a British company The present invention relates to apparatus for the distribution of pulverulent materials dispersed in a flowing fluid medium, and relates in particular to pulverised fuel, e.g., coal, dispersed in a gaseous medium such as air.

It is known that when such a dispersion of pulverised coal in a stream of air is transported by a piping system, e.g. to burners, the coal particles can become unevenly distributed over the crossasectiona-l area of the piping, the particles concentrating in one part of the sectionalarea. Such concentration occurs in particular after a change in direction, such as a bend in the piping, centrifugal force acting on the particles to effect concentration in the plane of thebend.

=When it is desired to divide such a stream between two branches of a piping system it is necessary to employ special means to ensure that the concentrated portion of the main stream does not preferentially enter one branch rather than the other, but is divided between the two branches as desired. Equal distribution between the two branches is usually required, but it may be desired to divide the stream into unequal branches. For example, a main stream could be divided into two branches, one branch stream being twice the size of the other, the larger branch being subsequently divided into two thereby producing three equal streams. It is also desirable simultaneously to divide both the air stream and the dispersed coal in order that combustion characteristics of the dispersion should be maintained.

One method hitherto employed for this purpose employs ritfle separation by means of a number of alternate slots in the plane of the last pipe bend before branching. This, it is hoped, scoops equal amounts of coal and air from the main stream into each branch. Unhappily the resulting division is frequently unequal and disproportionate.

According to the present invention, an apparatus for dividing a main stream of pulverulent material dispersed in a fluid medium between two branch streams comprises a fixed nozzle and a tiltable nozzle movable in the common plane of the branches, the fixed nozzle being arranged to direct the main stream into the tiltable nozzle, and the tiltable nozzle being arranged and adapted to bias the flow of the main stream variably between the branches.

The flow from the tiltable nozzle can be made more definite by mounting guide vanes within the tiltable nozzle.

'Ihe fixed nozzle may be formed by mounting cheek pieces within the pipe carrying the mainstream of fluiddispersed pulverulent material.

Manually operable means or automatic means may be provided for adjusting the inclination of the tiltable nozzle, and locking means may be incorporated to secure the tiltable nozzle in any desired inclination relative to the two branches.

The apparatus according to the invention may be used either alone or in conjunction with a conventional slotted riffle.

In operation the fixed nozzle deflects fuel concentrated at the periphery of the main stream towards its centre, and then deflects the stream into the tiltable nozzle. The inclination of the tiltable nozzle relative to the two branches is adjusted to bias the stream so that the required division is made between the two branches.

One embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which:

Fig. 1 is a vertical section of a distributor for air dispersed pulverised coal,

Fig. 2 is a vertical section about the line II- H of Fig. 1,

Fig. 3 is a plan section about the line IIIII-I of Fig. l, and

Fig. 4 is a plan section about the line IV'IV of Fig. 2.

In the drawings the distributor body comprises a main stream pipe'S, which divides into two branch pipes 6, 7. Cheek pieces 8 are bolted inside pipe '5 around a portion of its periphery to produce 'arestriction acting as a fixed nozzle 9. Between the fixed nozzle 9 and a slotted riffle 10 arranged at the junction of pipe 5 with branch pipes 6, 7, a tiltable nozzle 11 is mounted on short spindles 12, 13, carried in bearings 14,. 15, respectively, and the nozzle 11 is pivotable about axis 16. Two of the possible alternative positions for tiltable nozzle 11 are shown in Fig. 2 by means of broken lines at 11a and 11b respectively. A control lever 17 is mounted outside pipe 5 on an extension 18 of spindle 13. The lever 17 may be secured in any desired position by clamping means 19.

The slotted riffle 10 is of wedge like form as seen in Figure 2, the side walls thereof being slotted in such manner that a slot in one wall is opposite a part of the other wall lying between two slots in the latter, i.e. a slotin one wall is not opposite a slot in the opposite wall.

In operation, the inclination of the tiltable nozzle 11 relative to branch pipes 6, 7, is adjusted by means of lever 17 to obtain the desired distribution of the air and pulverised coal between branch pipes 6 and 7. Manual operation of lever 17 is used in the embodiment of the invention described, but automatic control can be obtained by simple mechanical modification.

Distribution between the two branch pipes 6 and 7 is further improved by the slotted rilfle 10 which scoops amounts of coal and air from the main stream leaving the tiltable nozzle 11 and directs them into the branch pipes 6, 7.

'I claim:

1. Apparatus for dividing a main stream of pulverulent material dispersed in a fluid medium between two branch streams compirsing in combination a main ducting for containing the main stream, two branch pipes coupled to said main ducting for containing the branch streams, a fixed nozzle restriction located in and extending around the periphery of said main ducting, said fixed nozzle concentrating said main stream centrally in said main ducting, a tiltable nozzle disposed in and extending around the periphrey of said main ducting between said fixed nozzle and said branch pipes for receiving the concentrated main stream from said fixed nozzle and pivot means for said tiltable nozzle whereby the latter is tiltable in 'a plane containing both said branch pipes.

2. Apparatus for dividing a main stream of pulverulent material dispersed in a fluid medium between two branch streams comprising in combination a main ducting for containing the main stream, two branch pipes coupled to said main ducting for containing the branch stream, a fixed nozzle restriction located in and extending around the periphery of said main ducting, said fixed nozzle concentrating said main stream centrally in said main ducting, a tiltable nozzle disposed in and extending around the periphery of said main ducting between said fixed nozzle and said branch pipes for receiving the concentrated main stream from said fixed nozzle, guide vanes within said tiltable nozzle, and pivot means for said tiltable nozzle whereby the latter is tiltable in a plane containing both said branch pipes.

3. Apparatus for dividing a main stream of pulverulent material dispersed in a fluid medium between two branch streams comprising in combination a main ducting for containing the main stream, two branch pipes coupled to said main ducting for containing said branch streams, rib check members secured internally around the periphery of said main ducting for effecting a reduction in the cross sectional area thereof and concentrating said main stream centrally in said main ducting, a tiltable nozzle disposed in and extending around the periphery of said main ducting between said cheek members and said branch pipes for receiving the concentrated main stream from said fixed nozzle, and pivot means for said tiltable nozzle whereby the latter is tiltable in a plane containing both said branch pipes.

4. Apparatus for dividing a main stream 'of pulverulent material dispersed in a fluid medium between two branch streams comprising in combination a main ducting for containing the main stream, two branch pipes coupled to said main ducting for containing the branch streams, a fixed nozzle restriction located in and extending around the periphery of said main ducting, said fixed nozzle concentrating said main stream centrally in said main ducting, a tiltable nozzle disposed in and extending around the poriphery of said main ducting between said fixed nozzle and said branch pipes for receiving the concentrated main stream from said fixed nozzle, pivot means for said tiltable nozzle whereby the latter is tiltable in a plane containing in a plane containing both said branch pipes, and locking means for securing said tiltable nozzle in a desired position.

5. Apparatus for dividing a main stream of pulverulent material dispersed in a fluid medium between two branch streams comprising in combination a main ducting for containing the main stream, two branch pipes coupled to said main ducting for containing the branch streams, a fixed nozzle restriction located in and extending around the periphery of said main ducting, said fixed nozzle concentrating said main stream centrally in said main ducting, a tiltable nozzle disposed in and extending around the periphery of said main ducting between said fixed nozzle and said branch pipes for receiving the concentrated main stream from said fixed nozzle, a slotted riffle located in the junction between said branch pipes, and pivot means for said tiltable nozzle whereby the latter is tiltable in a plane containing both said branch pipes.

References Cited in the file of this patent UNITED STATES PATENTS 1,757,634 Jacques May 6, 1930 1,911,543 Bailey May 30, 1933 FOREIGN PATENTS 637,319 Great Britain May 17, 1950 

